IE7 refuses to install

I'm stuck with IE6 as IE7 refuses to install, I've tried nearly everything bar reinstall of windows. It seems the install of IE7 needs write-access to the two registry keys:
HKLM = HKEY_LOCAL_MACHINE
HKCR = HKEY_CLASSES_ROOT
...but I get access denied to these keys no matter which account I use, including the safemode admin account. Anyone any ideas how to resolve this?

Hi Globalforce,
yeah part 2 on that support page is where the issue lies I think, no matter what I try it won't let me have access to change the permissions on those registry keys.
You think messed up security identifiers could be causing this? What can cause this, is there a way of checking or fixing this without a reinstall?

Unless your running a security program that's protecting, I'd say there's a problem not being able to access those key's as Administrator.
And yes, I think we can straighten this out without a you know what!

Please upload a copy of your IE7.log file as an attachment, I'd like to have a look.
Could you verify having erunt installed?

Unless your running a security program that's protecting, I'd say there's a problem not being able to access those key's as Administrator.
And yes, I think we can straighten this out without a you know what!

Please upload a copy of your IE7.log file as an attachment, I'd like to have a look.
Could you verify having erunt installed?
GF

Do you think that MS will rectified the situation so we don't have to try many manipulations just to try to update our IE because if that's the case I will simply wait... I sure don't want to bother installing a simple update to IE.